Unable to select circle in G 1 because off the screen

I have Slick Social Share Buttons installed on https://www.chocolateboxcoaching.co.uk. A visitor reported that she had tried to share an article on Google Plus, but wanted to select a particular circle to share with. However it would appear that the size of her screen means that she can’t see the bottom of the G+1 miniscreen that opens, and it is impossible to scroll down, because the Buttons just scroll down too. I have the buttons set at Floating, Top right and offset by 50px. Are there any settings I could change to to overcome this problem?

https://www.ads-software.com/plugins/slick-social-share-buttons/